From e89cfe51d2001af08fc2a13e5133ba8157f90beb Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Tue, 1 Jul 2014 18:27:19 -0400 Subject: fix aliasing violations in mbtowc and mbrtowc these functions were setting wc to point to wchar_t aliasing itself as a "cheap" way to support null wc arguments. doing so was anything but cheap, since even without the aliasing violation, it would limit the compiler's ability to optimize. making wc point to a dummy object is equally easy and does not suffer from the above problems. --- src/multibyte/mbtowc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'src/multibyte/mbtowc.c') diff --git a/src/multibyte/mbtowc.c b/src/multibyte/mbtowc.c index 6710637a..803d2213 100644 --- a/src/multibyte/mbtowc.c +++ b/src/multibyte/mbtowc.c @@ -12,10 +12,11 @@ int mbtowc(wchar_t *restrict wc, const char *restrict src, size_t n) { unsigned c; const unsigned char *s = (const void *)src; + wchar_t dummy; if (!s) return 0; if (!n) goto ilseq; - if (!wc) wc = (void *)&wc; + if (!wc) wc = &dummy; if (*s < 0x80) return !!(*wc = *s); if (*s-SA > SB-SA) goto ilseq; -- cgit v1.2.1